. >> this gives us the ability to know what the critical times are and it helps us to protect public safety by allocating resources in the county where the need to be. >> those storm water management folks have been working around the clock. they say they're looking at the potomac river and all of its tributaries to see if it will cause trouble for the neighborhoods and streets as well. >> calvert county was hit hard by the storms and heavy rains. they had just gotten home from work when a 40-foot tree hit their house. they were not hurt in this. in prince george's and anne arundel counties, where some of the heart -- some of the hardest rain fell today, we are live. >> it is at the epicenter of a lot of problems. you can see high water down that direction down highway 450. down here, you can see road closed signs and about 100 feet down, there's water coming across the road. what a dicey day. >> if you are going to fast you will probably go off the road. >> it seems like the rain came down and only hours wednesday. it proved potentially dangerous and particularly difficult in anne a